North Korea's foreign ministry on Sunday called on the United Nations to demand an immediate halt to joint military exercises between the United States and South Korea, saying the exercises escalate tensions that threaten to spiral out of control.

Vice Foreign Minister Kim Sun Kyung said in a statement carried by the KCNA news agency that the exercise was an "irresponsible escalation of tension".

He described the military cooperation between South Korea, Japan and the United States as a step that crossed red lines and could not be accepted.

For its part, the newspaper "Chosun Shinbo" - issued by a pro-North Korean organization in Japan and mouthpiece for Pyongyang - described the US-South Korean exercises as a rehearsal for the invasion of North Korea.

North Korea's foreign ministry earlier Saturday blamed the United States for what it described as the collapse of international arms control regimes, and said Pyongyang's nuclear weapons were a just response to ensure the balance of power in the region.

The ministry added in a statement that the Korean peninsula has turned into the largest barrel of fuel and a battlefield in the world as a result of the military expansion policy pursued by the United States and its followers.

Joint maneuvers

South Korea and the United States announced the day before yesterday, Friday, that they intend to start a joint military exercise later in March, while striving to strengthen deterrence against North Korea's advanced nuclear and missile threats.

And the South Korean Yonhap News Agency stated that the "Freedom Shield" exercise is scheduled to take place between March 13 and 23, according to the joint chiefs of staff in South Korea and the US forces in Seoul.

North Korea has been subject to strict international sanctions for years because of its nuclear weapons and ballistic missile programs, and US, European and Chinese intelligence say that North Korea has between 20 and 60 usable nuclear warheads, according to the US news site VOX.

According to US intelligence as well, it is assumed that North Korea is now able to install a nuclear warhead on its intercontinental missiles, which can extend the US west coast, in addition to Hawaii and the US "Guam" base in the Pacific Ocean and Alaska.